When a site shows a vague error or a blank white screen, the actual cause is almost always recorded in the server's error log — you just need to know where to find it and how to read it.
Finding the error log in cPanel
Look for Errors under the Metrics section of cPanel — this shows the most recent entries from your domain's error log automatically, without needing to download or open any file manually.
Reading a typical log line
A line usually starts with a timestamp, followed by the error type (like PHP Fatal error or PHP Warning), a description of what went wrong, and the exact file path and line number where it happened — that file and line number is the most useful part for tracking down the cause.
Common WordPress errors and what they mean
"Allowed memory size exhausted" means a plugin, theme, or PHP process needs more memory than your hosting plan allows for that request — often fixed by increasing the PHP memory limit or disabling a heavy plugin. "Call to undefined function" usually means a plugin was deactivated or a file was deleted while something else still expects it to exist. A blank white screen with nothing visible is frequently a fatal error that the error log will explain even when the browser shows nothing at all.
Increasing the PHP memory limit
This can often be raised from cPanel's MultiPHP INI Editor, or by adding a line to wp-config.php — check with your host first, since some plans have a hard ceiling regardless of what you set in WordPress itself.
Turning on WordPress debug mode (temporarily)
Setting WP_DEBUG to true in wp-config.php shows errors directly on the page instead of just logging them silently — useful for isolating an issue, but should be turned back off once you're done, since it can expose file paths publicly if left on.
When to contact hosting support
If the log references a server-level issue rather than a specific plugin or theme file — timeouts, resource limits being hit repeatedly, or errors in core server processes — that's the point to hand the exact log line to your host's support team rather than trying to diagnose it further yourself.
Key takeaway: The error log almost always names the exact file and line causing the problem — copy that exact line when asking for help, whether from a developer or hosting support, rather than describing the symptom in general terms.